What was the primary purpose of motor generator sets on older elevators?

Motor generator sets were primarily designed to convert alternating current (AC) power into direct current (DC) power for older elevator systems. This conversion was crucial because many of the early elevator systems relied on DC motors for their operation due to their ability to provide better torque and speed control compared to standard AC motors at that time.

In older building designs, elevators utilized direct current motors that depended on this conversion to function effectively. As a result, the reliability and efficiency of the elevator system were significantly enhanced by using motor generator sets, ensuring smooth and consistent operation.

While other functions, such as providing emergency lighting or controlling door operations, are important for elevator safety and functionality, they are secondary to the primary role of the motor generator set in facilitating the power conversion necessary for the operation of DC motors in the elevator systems.